diff --git a/lib/client/message-tracker/index.js b/lib/client/message-tracker/index.js
index 6c71b68..198f1cb 100644
--- a/lib/client/message-tracker/index.js
+++ b/lib/client/message-tracker/index.js
@@ -104,7 +104,7 @@ module.exports = function messageTrackerFactory (options) {
       return { message: abandonedMsg, callback: abandonedMsg.cb }
     }
 
-    return null
+    return { message: null, callback: null }
   }
 
   /**